Controlled toggle mechanisms

ABSTRACT

A MECHANISM FOR OPERATING A WORK ELEMENT FROM ONE SELECTED POSITION TO OTHER SELECTED POSITIONS IN SUCCESSION IS DESCRIBED, UTILIZING THE SPECIAL PROPERTY OF TOGGLES SO THAT THE END POSITION IS REACHED WITH SMOOTH DECELERATION AND WITHOUT OVERTRAVEL. MULTIPLE TOGGLES HAS AN INPUT END THAT IS EMBODIMENTS, WHERE EACH TOGGLE HAS AN INPUT END THAT IS ADJUSTABLE WHILE THAT TOGGLE IS BUCKLED TO CORRESPOND TO THE DESIRED POSITION THAT THE WORK ELEMENT WILL REACH WHEN A POWER ACTUATOR ERECTS THE TOGGLE. ONE TOGGLE IS USED FOR DRIVING THE WORK ELEMENT IN ONE DIRECTION AND ANOTHER TOGGLE IS USED WHEN THE WORK ELEMENT IS TO BE DRIVEN IN THE OPPOSITE DIRECTION. FOUR TOGGLES ALLOW FOR DRIVE IN EITHER DIRECTION BY ONE TOGGLE WHILE ANOTHER TOGGLE IS AVAILABLE FOR ADJUSTMENT IN CONTROLLING THE NEXT MOTION IN EITHER DIRECTION. THIS SAVES TIME, ENABLING EACH STROKE TO FOLLOW ANOTHER WITHOUT DELAY FOR ADJUSTMENTS. THE SELECTIVELY USED TOGGLES CAN BE COMPACTLY ARRANGED SIDE-BY-SIDE AT THE SAME SIDE OF A WORK SHAFT BUT CONNECTED TO OPPOSITE SIDES OF THE SHAFT, TO ROTATE THE SHAFT IN EITHER REQUIRED OPERATING DIRECTION. SIMILARLY, A COMMON ADJUSTING UNIT CAN BE USED FOR ALL THE TOGGLES, UTILIZING EXTENSIBLE AND CONTRACTABLE COUPLINGS BETWEEN THE ADJUSTING UNIT AND THE ADJUSTABLE TOGGLE ENDS.

July 30, 1974 G. c. DEVOL CONTROLLED 'I'OGGLE MECHANISMS 5 Sheets-Sheet1 Original Filed Aug. 26, 1968 My 1974 e. c. DEVOL Re. 28,089

CONTROLLED 'I'OGGLE MECHANISMS Original Filed Aug. 26, 1968 5Sheets-Sheet a v v a/04A I ,wqg l 1 4/901! 775 1 774% f, d 512 a 74461/071 gm I I L Q gin (oz/P10? a 96 4 y 1974 G. c. DEVOL Re. 28,089

CONTROLLED TOGGLE MECHANISMS Original Filed Aug. 26, 1968 5 Sheets-Sheet3 Ma 96a --f j y5@ 58 W 504 V5 W) y 1974 s. c. DEVOL Re. 28,089

CONTROLLED TOGGLE uzcnmxsus original Filed Aug. 26, 1968 5 Sheets-Sheet5 United States Patent 'Oflicc Re. 28,089 Reissue-d July 30, 1974 Int.Cl. G05g 1/04 US. Cl. 74-520 35 Claims Matter enclosed in heavy bracketsappears in the original patent but forms no part of this reissuespecification; matter printed in italics indicates the additions made byreissue.

ABSTRACT OF THE DISCLOSURE A mechanism for operating a work element fromone selected position to other selected positions in succession isdescribed, utilizing the special property of toggles so that the endposition is reached with smooth deceleration and without overtravel.Multiple toggles are used in a few embodiments, where each toggle has aninput end that is adjustable while that toggle is buckled to correspondto the desired position that the work element will reach when a poweractuator erects the toggle. One toggle is used for driving the workelement in one direction and another toggle is used when the workelement is to be driven in the opposite direction. Four toggles allowfor drive in either direction by one toggle while another toggle isavailable for adjustment in controlling the next motion in eitherdirection. This saves time, enabling each stroke to follow anotherwithout delay for adjustments. The selectively used toggles can becompactly arranged side-by-side at the same side of a work shaft butconnected to opposite sides of the shaft, to rotate the shaft in eitherrequired operating direction. Similarly, a common adjusting unit can beused for all the toggles, utilizing extensible and contractablecouplings between the adjusting unit and the adjustable toggle ends.

The present invention relates to apparatus capable of executing powerstrokes to various accurately controlled positions, especially underprogram control, but also by control from a remote point, and undermanual control. The invention is more specifically related to apparatushaving plural adjustable power actuators to carry out motions to asequence of positions, where each motion has components in pluraldegrees of freedom. The apparatus described by way of illustration is anarticle-transfer machine, but the invention is broadly useful in otherapplica tions as, for example, X-Y tables.

A broad object of the invention resides in providing a toggle-type poweractuating apparatus for operating a load to a succession of positions,including successive strokes in the same direction or in reversedirections as may be required.

A toggle is an ideal type of mechanical linkage for producing a rapidstroke with considerable power, having the prominent characteristic thatthe working end of the toggle decelerates smoothly as the toggleapproaches its erect or straight state. Consequently, the load moved bythe toggle decelerates smoothly as it reaches the end-point of eachmotion.

A more particular object of the invention resides in providing adual-toggle actuator whose motions are adjustably controlled to carry aload or object through successive strokes of adjustable length, or tovaried end-points, or from any starting position to any end position ofthe range of the toggles, all power strokes ending accurately with thetoggle erect.

In achieving the foregoing objects, paired toggles are connected to aload, arranged to execute their erecting,

powerstrokes in opposite directions. Depending on the desired directionof motion of the load from any given position to the next, one or theother toggle of the pair is to execute an erecting stroke. The input endof at least that toggle is adjustably set in a preliminary operation.The knee of the toggle is then driven by a power actuator to erect thetoggle, driving the load to an end position determined by the adjustedsetting of the input end of the toggle.

An elemental example of a controlled-stroke toggle actuator is disclosedin my Pat. No. 3,279,624 (FIG. 2) granted Oct. 18, 1966, but in thatconstruction the toggle operates its load in only one direction and apower clamp produces the return motions without realizing the benefit ofthe toggle operating characteristics.

A further object of the invention is to provide for minimizing the timelost in adjusting the input end of the toggle or toggles to a successionof control positions. A pair of toggles are used for operations inopposite directions, each having an input end that is to be adjusted. Acommon adjustment means is used for adjusting the input ends of both ofthe toggles. In one embodiment of the invention that has only one pairof toggles, the adjustment means operates during the time that eithertoggle is executing a. power stroke and has its input end locked in aprevious adjustment. Completion of the setting operation occurs betweeneach toggle stroke and the next. In a further embodiment of theinvention, the apparatus is equipped with two pairs of toggles, andthere is a common means of adjustment for the input ends of all thetoggles. One toggle of each pair executes a forward power stroke and theother toggle of that pair execute a reverse power stroke of theapparatus. The forward-acting toggle of one pair is available to beadjusted and ready for executing an ensuing forward stroke during thetime that the forward-acting toggle of the other pair is executing anoperating power stroke of the apparatus. By like token, the input end ofthe reverse-acting toggle of one pair is adjusted while the otherreverse-acting toggle is in a power-stroke operation. The adjustment ofa toggle that is to execute the next power stroke is completed during apresent power stroke of the apparatus, regardless of whether the twostrokes are in the same or opposite directions.

A still further aspect of the invention resides in the provision ofmeans for utilizing a single adjustment means for setting the input endsof each of the toggles. Usually, a coupling device is provided betweenthe adjustment means and each of the input ends of the toggles toaccommodate the locked setting of the input end of the toggle that isexecuting a power stroke during the adjusting operation. Where one pairof oppositely acting toggles is used, the coupling device quicklyadjusts the input end of the toggle that is to operate next so as toconform to the setting of the adjustment means. Where two pairs oftoggles are used, the coupling devices are effective in setting onetoggle into its adjusted condition conforming to the common adjustmentmeans while another toggle is carrying out its power stroke and itsinput end is locked in a previously adjusted setting.

Further objects and novel features are pointed out in the followingdetailed description of a few embodiments of the various aspects of theinvention, and from this description the foregoing objects and featureswill be more fully understood and appreciated. The accompanying drawingsform part of the disclosure of the described embodiments.

In the drawings:

FIG. 1 is an elevation of an article handling machine embodying featuresof the invention;

FIG. 2 is a diagrammatic lateral elevation of a presently preferredoperating mechanism for each of three parts zaoss l of the apparatus inFIG. 1, embodying further features of the inventiont FIG. 3 is adiagrammatic lateral elevation of another presently preferred operatingmechanism for each of three parts of the apparatus in FIG. 1, being amodification of the embodiment in FIG. 2;

FIG. 3A is a modification of a detail of FIGS. 2 and 3;

FIG. 4 is a plan view of the operating mechanism of FIG. 3, includingstructural details;

FIG. 5 is a front, elevation of the mechanism in FIG. 4;

' FIG. 6 is a vertical cross-section of the mechanism in FIG. 4 viewedfrom the plane 6-6 in FIG. 4;

FIG. 7 is a wiring diagram of control apparatus for the embodiment ofFIG. 3;

FIG. 7A is a timing diagram of a portion thereof;

FIGS. 8-11 are diagrammatic lateral elevations of a modification of FIG.2 in various operating phases; and

FIG. 12 is a diagram of apparatus for controlling the operatingpositions of the modification of FIGS. 8-11.

An article handling machine is shown in FIG. I, having a fixed base 10,a secondary base 12 and a post 14 supported by base for rotation as aunit about a vertical axis, and a boom or arm 16 movable in a verticalare about pivot 18. Head 20 of the machine is supported by a rod 22 forin-and-out motion relative to arm 16, a motion that is radial inrelation to the vertical axis of post 14. These three motions in as manydegrees of freedomrotation about the vertical axis, arcuate about pivot18 and radial-represent the three heaviest work loads of the machine,more fully discussed below.

Head 20 carries article-gripping jaws 24 and contains gearing (notshown) for effecting a pivotal motion or wrist-bend about horizontalaxis 25 perpendicular to the view and for effecting a twist motion aboutan axis midway between jaws 24, parallel to the view. A suitableactuator in head 20 such as a hydraulic piston (not shown) opcrates jaws24 to grip and release an article. The internal details of head 20 areshown and described in detail in my Pat. No. 3,306,471, granted Feb. 28,1967.

A pair of hydraulic cylinders 26 operating a chain 28 about a sprocket30 operates the wrist-bend gearing in head 20, and another suchmechanism operates the twist mechanism in head 20. Both operatingmechanisms operate through splined shafts from head 20 to arm 16. Otherdetails are fully described in my Pat. No. 3,306,471. These motionsrequire comparatively modest operating effort. Insofar as speed,acceleration and deceleration are concerned, the load to be operated ismoderate. The moment of force exerted by head 20 is limited, as is thearticle weight to be carried. The twist and wrist motions involverelatively slight moments since they take place about axes locatedrelatively close to the center of head 20 or of the article in jaws 24.

Head 20 is moved radially by a rack 32 and gear 34, a sprocket 3'6 fixedto gear 34, a chain 38, and another sprocket 40 fixed to main drive gear42. Head 20 is moved in a vertical arc about pivot 18 by a rack 44 thatis in mesh with gear 46. Rack 44 is pivotally connected to arm 16.Sprocket 48 is fixed to gear 46 and is driven by chain 50 that alsoextends about drive sprocket 52. Main drive gear 54 is fixed to sprocket52. Secondary base 12 and the post 14 and arm 16 carried thereby areoperated about their vertical axis by main drive gears 56. In FIG. 1,the main drive gear 56 is shown in mesh with two racks 58 and 58aforming part of the operating apparatus described below.

In contrast to the relatively light loads involved in the twist andwrist motions, head 20 is moved radially through a long stroke in alimited time interval, and represents a substantial work load to bemoved and arrested by the related operating mechanism. Ann 16 alsorepresents a 'large work load that is to be accelerated and deceleratedarcuately about pivot 18 by the arm-actuating apparatus. Finally, alarge torque, acceleration and deceleration must be developed by themechanism that rotates secondary base 12 and post 14 about a verticalaxis. This drive effort must also swing arm 16, head 20 and the articlein jaws 24, about the vertical axis of post 14.

FIG. 2 illustrates a highly effective and relatively simple form ofpower actuator for effecting controlled operations of each of the maindrive gears 42, 54 and 56 in FIG. 1. In the discussion that follows,only gear 56 is mentioned, but the other two gears are operable byduplicate mechanisms contained in the secondary base 12. The mechanismfor operating gear 56 is contained in base 10. Gear 56 in FIG. 2 hasfixed bearings. Secured to gear 56 is a brake drum 60 that may be lockedby a brake shoe 62. A pistonand-cylinder actuator 64 having a controlvalve 66 and a compressed air or hydraulic fluid supply line is used tooperate the brake.

Racks 58 and 58a are in mesh with gear 56 and are slidable in suitablebearings. A toggle consisting of links 68 and 70 are pivoted together ata knee 72. Input end 74 and output end 76 of the toggle are guided insuitable slide bearings aligned with rack 58. Knee 72 has a piston rod78 connected to it, for operation by fluid pressure admitted to cylinder80 under control of valve 82. The lower end of the cylinder is pivotedso that the actuator 78, 80 can follow the knee of its toggle throughoutthe range of operating positions. The pressure drives the toggle from abuckled condition to an erect condition, but not beyond the erectcondition due to suitable limiting means in the knee of the toggle or anelongated stop in line with the toggle ends. A small compression spring84 in cylinder 80 provides bias that urges knee 72 of the toggle out ofline with the ends of the toggle (when there is no pressure in cylinder80) so that lengthwise pressure at the input end of the toggle willbuckle the toggle.

Input end 74 of the toggle is adjustable, and can be locked at any placewithin its maximum range. For this purpose, a block 86 is provided inwhich input end 74 of the toggle is pivoted. Block 86 is suitably guidedbetween a fixed brake shoe 88 and another brake shoe 90. Fluidpressureactuators 92 are operated by pressure admitted via control valve 94 tolock block 86 and input end 74 of the toggle in any adjusted position.

A coupling device 9 is slidable alongside the toggle links 68 and 70 andalongside rack 58, but for clarity coupling device 96 is shown in FIG. 2below its actual position, the coupling device includes an outerfluid-pressure cylinder 98, a piston 100 and a fluid-pressure inletvalve 102. Piston rod 104 is hollow and contains a piston 106 that isconnected by rod 107 to adjustable input end 74 of the toggle. Tubularrod 104 has an opening adjacent piston 100 to admit and discharge fluidfrom or to cylinder 98. Of particular significance is this: Whenpressure is admitted to cylinder 98, and when rod 108 is not restricted,piston 100 moves to its right-hand extreme position and piston 106 movesto its left-hand extreme position. In this configuration coupling device96 is in its mean-length condition. The end of device 96 connected toinput end 74 of the toggle can move toward cylinder 98 for a distance atleast as great as the maximum stroke of rack 58, thus shortening device96. Piston 106 can pull piston 100 leftward in cylinder 98 for adistance at least as great as the maximum stroke of rack 58. In theposition of the parts of device 96 shown, the length of device 96 is amean, and is limited by pistons 100 and 106 reaching their right-handand left-hand limits, respectively. This condition is established bypressure in cylinders 98 and 104. In concept, this could be a sustainedpressure, or it could even be supplied by springs in those cylinders,essentially as shown in FIG. 4 of my Pat. No. 3,279,624.

Rack 58a is operable by a duplicate of the described toggle mechanism,including toggle links 68a, 70a, a fluid-pressure actuator having apiston rod 78a operable in a power stroke to erect the toggle, andhaving an input end of the toggle 74a in block 86a adjustable alongbrake shoes 88a and a. Block 86a can be arrested in any adjustedposition by actuator 92a of the fluid-pressure brake or lock and itscontrol valve 94a. Finally, a coupling device 96a is shown above thetoggle and the rack for clarity. Device 96a is shown in its mean-lengthcondition, with pistons 100a and 106a in their extreme righthand andlefthand positions in their cylinders, respectively.

Fixed to each cylinder 98, 98a remote from the input end 74, 74a of itsrespective toggle is a block 108, 108a that is slidably guided parallelto racks 58, 58a. These are connected by an equal-arm lever 110 forreverse operations. Block 108 is shown in its extreme left-hand positionand block 108a is shown in its extreme right-hand position. Lever 110has a fixed pivot 112 at its center. The extremities of lever 110 havesuitable slide bearings in blocks 108, 108a accommodating the arcuatemotion of the lever ends to the linear motion of the blocks.

Means is provided for enforcing motion of block 108 to the right and tothe left to exactly controlled positions. A suitable adjusting device114 for this purpose is a column of double-acting fluid-pressureactuators 116 each having a control valve 118 to admit fluid underpressure selectively to the right or the left end of its cylinder fordriving its piston to the opposite extreme position. The valve vents theopposite end of the cylinder or, in the case of hydraulic fluid, thevalve releases the fluid to the low-pressure part of the system. Thestroke of each piston in its cylinder is a precisely establisheddimension. To advantage, one fluid-pressure actuator 116 has half themaximum stroke required of racks 58, 58a, another has half that stroke,and so on in progression to the smallest desired increment of motion ofthe racks. Each piston acts on the cylinder of the next actuator in thiscolumn. Together the actuators can drive blocks 108 and 108a to theiropposite extremes by pulling or pushing block 108.

Various combinations of cylinders can be actuated to the right and tothe left, in this way driving block 108 to any desired position withinan increment limit determined by that actuator 116 which has thesmallest stroke. A binary-code program recording on punched tape ormagnetic recording or any other control medium may be used to controlsolenoids 120 to actuates valves 118 selectively; and a manual controlhaving a binary numerical-code pattern of perforations or contacts orthe like can also be used to control solenoids 120. Controls of thistype are shown in my Pats. Nos. 3,251,483, 3,279,462 and 3,283,918. MyPat. No. 3,729,624 also shows other forms of program controls assuitable substitutes for the illustrated adjustable means 114.

The operation of the apparatus in FIG. 2 is as follows. It may beassumed that all of the actuators 116 are extended, that valves 102 and102a have pressurized coupling devices 96 and 96a, and that actuator 80and its companion actuator for rod 78a have been caused by their contolvalves 82 to erect the upper and lower toggle 68, 70 and 68a, 70a. Thiscondition places gear 56 (or 42 or 54, as may be the case) at theclockwise limit of its range. The next motion is to be a controlledcounterclockwise rotation of gear 56. Before any change occurs amongcylinders 116, gear 56 is locked in position by setting brake 60, 62.Pressure in actuator 80 is released, and valve 102a vents couplingdevice 96a. Spring 84 biases toggle 68, 70 toward its buckled state, andthis toggle becomes buckled (see the broken lines) when cylinders 116 inany selected combination retract their pistons so as to pull block 108to the right. Piston 106a of coupling device 96a is stationary. Whenblock 108 moves to the right, block 108a moves to the left and cylinder104a moves to the left along rod 107a of piston 106a.

The new adjustment of the control portion of the apparatus is nowcomplete. In this instance, assembly 114 has acted via block 108 andpressurized coupling device 96 to shift the input end 74 of toggle 68,70 toward the right. Unit 114 preferably sets before coupler 96 works.Valve 94 is next operated to cause actuators 92 to clamp or lock theblock 86 in place, fixing the adjustment of the input end of the toggle.

Valve 82 is next used to cause actuator to pull its rod 78 in a powerstroke to erect toggle 68, 70 and at the same time or a moment earlier,brake 60, 62 is released. Rack 58 is driven to the right, rotating gear56 counterclockwise in a powered motion to the extent determined by theadjustment of the input end of the toggle. During this motion, valve 94areleases block 86a, and as one mode of operation, toggle 68a, 70a mayremain erect. Rack 58a shifts to the left when gear 56 executes itspowered motion under control of toggle 68, 70. Toggle 68a, 70a shifts tothe left, and draws piston 106a back to its illustrated relationship toits cylinder 104a. Brake 60, 62 is then set by its actuator 64, andlocks and 90a at the input ends of the toggles are released. Theapparatus is now ready for the next stroke. If further counterclockwiserotation of gear 56 is wanted, the same operations as described arerepeated.

Let it now be considered that the gear 56 in FIG. 2 is not at itsextreme clockwise limit of its range, and that the next operation is tobe clockwise rotation of gear 56. The appropriate combination ofactuators 116 is operated to move block 108 to the left, to the exactextent desired. Parts 98a and 108a shift to the right. Coupling device963. is pressurized at this time, to bias its parts to assume their meanpositions as shown. Toggle 68a, 70a collapses to the extent required toaccommodate the adjustment of its input end 7421 to its fixed outputend. During this motion, while gear 56 is locked, piston 106 is fixed inposition by its erect toggle 68, 70 and rack 58, all of which isarrested while gear 56 is locked. Apart from piston 106, the rest ofunit 96 shifts leftward with block 108 in this operation. A sequence ofoperation is then carried out as in the case of the lower toggle forcausing the upper toggle to execute its power stroke.

A manual combination-code controller for actuators 116 or a programcontroller is changed from one positionselecting setting to another.After blocks 108 and 108a are set, the side of the apparatus that is notto execute a power stroke is conditioned opposite to that for the sidethat does execute a power stroke. Either the brake 90 or 90a or theactuator rod 78 or 78a or both are released on the side of the apparatusthat is not to execute a power stroke. This is taken into account byproviding a direction-of-motion control for the control valves of theupper or the lower toggle, in addition to the combination-code controlthat determines the next position. This directionof-motion control isincluded with the manual control and as part of a control program.

A further feature is achieved in the apparatus of FIG. 2, for speedingthe squence of operations. As soon as one brake 90 or 90a is locked, itis possible immediately to continue with another setting of theadjustment assembly 114. Thus, suppose block 86 were newly adjusted inposition by pressurizing coupling device 96 so that input end 74 of thelower toggle agrees with the setting of block 108, and suppose thatblock 86 is then locked in place to control the ensuing power stroke ofthe toggle 68, 70. A new rightward adjustment for block 108 canimmediately be started by contracting the assembly of actuators 116 tothe required extent. This is made possible by the provision of cylinder98 and piston 100 in the cylinder of coupling device 96. As block 108 isdrawn to the right while block 86 is locked in plate, piston 100 remainsat rest while its cylinder 98 is drawn to the right. The provisions ofpiston 106 and cylinder 104 in coupling device 96 similarly accommodatesleftward shift of block 108. A new setting for block 108 is thusestablished during the same period that is allowed for either toggle toperform its power stroke. Immediately afterward, brake 60, 62 is setmomentarily and locks gear 56 in place. Block 86 or 86a is thenreleased, to be driven to the next setting by pressurized couplingdevice 96.

It would be feasible to omit coupling devices 96 and 96a in theforegoing apparatus. Actuators 116 would be selectively pressurized toestablish each new setting of block 86 or 86a. However assembly 114 inthat case is not positive-acting and would assume its intended lengthonly when brake 62, 64 is locked and blocks 86, 86a are released.

A further saving in time is realized pursuant to the embodiment in FIG.3. The parts corresponding to those in FIG. 2 are distinguished by aprefix a or b (except that the adjusting assembly 114 is the same) andcarry the same numbers. Gear 56 and another gear 56' are both fixed tocommon shaft 56a which is the output shaft of the whole apparatus.

Brake 60, 62 of FIG. 2 has been omitted in FIG. 3. Two pairs of togglesare used for operating gear 56-56, to gether with two coupling devicesfor each pair of toggles and two pairs of brakes for locking the inputends of the two pairs of toggles, respectively. Blocks a108 and b208 areunited and are driven to the right and left by unit 114.

In FIG. 3, toggle a68-a70 is shown partially collapsed, with itscoupling device pressurized and its adjustable input end a74 set inaccordance with the control code that established the length of theadjusting assembly 114. At this time at least one of brake elementsa90a, b90, and b90a is operative to hold the input end of its relatedtoggle locked, and that related toggle is being operated by itspressurized power actuator (not shown) connected by actuator rod a78a,b78 or b78a to the knee of its toggle. Under this condition theoperation and end positions of gear 56-56 are fully under control ofthat toggle. Meantime, the extent that toggle a68, a70 is beingcollapsed and having its input end set, is determined by the adjustingmeans 114 and the coupling device a96. The other coupling devices a96a,b96 and b96a are not pressurized, and in each instance one of thepistons is displaced relative to its cylinder by a distance A whichequals the displacement of input end a74 of the lowermost toggle in thedrawing from the position it occupied just previously when its togglewas straight.

Following the adjustment of input end a74 of toggle a68, a70, its blocka86 is located by brake element a90. It is then in condition to controlthe extent of counterclockwise drive of gear 56-56. The power actuatora80 of rod a78 is pressurized, and at that time or earlier, blocks a86a,b86 and b86a are all released and in condition to accommodate theadjustment of any other input end a74a, b74 or b74a by adjustingassembly 114, etc. Two successive steps of motion can be executed inquick succession, whether in the same or opposite directions. Duringeach power stroke of the output end a76, a76a, b76 or b76a of one of thetoggles, the adjusting means 114 and the input end of another of thetoggles are adjusted to be ready for the next stroke. It will beunderstood that the program control means of the apparatus or the manualcontrols if the machine is under manual control) includes provision forcontrolling the various brake actuators 92, the various power actuatorsfor the toggle knees, and for pressurizing coupling devices 96selectively, so as to select the toggle that is in effect at any onetime and the toggle that is being set at that time to produce the nextoperating stroke.

The rack-and-gear couplings between the toggles and the shaft rotated bygear 56 may be made accurately for minimum play or error between forwardand reverse operations, or anti-backlash gearing may be used; or (FIG.3A) a flexible but inextensible band 121 may be secured to bars A58 andA58a in lieu of racks 2158 and a58a in FIG. 3) at a point remote fromthe output end of the related toggle, and arranged to extend along thebar and around drum A56 (in lieu of gear 56) to a secured point on thedrum.

The physical arrangement of the active parts in FIG. 3 are shown inFIGS. 4, 5 and 6. These figures will also serve to illustrate thephysical arrangement oflike parts of FIG. 2. In FIG. 4, the shaft 56athat couples gears 56 and 56' is illustrated'as being connected to adisc representing post 14 or either of the sprockets 40 or 52, dependingon where the apparatus in FIGS. 3-6 is used in FIG. 1. Where multiplemechanisms of this form are used to execute coordinated motions inmultiple degrees of freedom, it may be found advantageous to use someform of interlock among the toggles used in each'of the coordinatedstrokes. For example, series-connected switches can be mounted at therespective knees of the toggles that close when the toggles are erectedand have therefore completed their strokes. One switch 122" is mountedon link a68, to be closed by extension 124 of link a70. As discussedbelow, such switches should be connected in control relation to thesequencing operations of the various solenoid valves (such as valves 66,82 82a, 94, 94a, 102, 102a and the like) for-delaying subsequent strokesuntil the concurrent power strokes in all the degrees of freedom havebeen completed.

The description of the parts'in FIGS. 4-6 and their connection is notgiven here since it would amount to a repetition of the descriptionalready given in connection with FIGS. 2 and 3.

FIG. 7 is a wiring diagram of suitable control and coordinating meansfor the embodiment in FIGS. 3-6, partially in block-diagram form. Thiscontrol apparatus demonstrates a manner of carrying out automatically asequence of prescribed operations, and of establishing the desiredcontrol program initially.

In FIG. 7, a magnetic progrgam drum is shown equipped wtih a row ofmagnetic sensing heads 152 and 154. The drum has a surface layer ofmagnetically retentive material. An indexing mechanism 156 is providedfor advancing the drum stepwise, so as to dispose successive discreteareas opposite the sensing heads. A series of discrete areassimultaneously in sensing position is called a slot"; and the circularseries of discrete areas that are sensed successively by any one sensinghead is called a track. The sensing heads in this particular example ofcontrol apparatus is the well-known at res" sensing type. The recordingheads are shown as separate units for convenience in illustration, butcommonly both the sensing and recording functions are performed by acommon read-write head, conveniently including sepa rate read and writewindings. In lieu of the indexed type of drum,, it is evident that drumshaving a sensing gate circuit could be substituted, and other controlmedia may also be substituted.

Heads 152 and 154 are divided into groups, including separate groups152ea and 154a for the operating mechanism (FIGS. 3-6) that is used ineach degree of freedom in the apparatus of FIG. 1. Additionally, thereare sensing and recording heads 152b and 15% for controlling thecoordination of the operating mechanisms and for coordinating thefunctions of the apparatus of FIG. l, with external apparatus, generallyin the manner set forth in my Pat. 3,251,483.

Temporary storage registers 158a and 158b are provided for each group ofsensing heads 152a and for group sensing heads 158b, coupled thereto bysuitable transfer switching means 160a, 16%. This switching means isshown as being part of a relay 160, although in practice solid-stateswitching may well be used. The storage solenoids 120 for control valves116 in FIG. 3. Selector switching means 162a is included for connectingsolenoids 120 either to the storage register 158a as shown, or to amanually operable digital encoder 164. The code used is preferably ofthe type in which only one bit of the code changes in advancing from anygiven position to the next adjacent position requiring a code change.

Switching means 162b is also included, for connecting function-controland coordinating relays 178 either to 9 storage register 158b or tomanual controls, for purposes discussed more fully below.

When a program is to be established initially, switching means 162a isarranged to connect encoder 164 to solenoids 120. By reversing switch162b from the position shown, and by using manual controls for thevarious valves in the apparatus, the work head 20 (FIG. 1) is adjustedto a desired position. Thus, assembly 114 is progressively adjusted tothe length required to locate head 20 at the desired position. Duringthis operation, the related coupling device a96 (for example) is keptpressurized, and pressure is supplied to actuator a80 for keeping iterect. In this slow operation, it is assumed that pistons 116 can supplythe requisite efiort. Otherwise a process of trial-and-error adjustmentof assembly 114 and clamp a94, then actuator a80, could be used. Whenthe desired adjustment is reached, the code of unit 164 is entered ondrum 150 by the related group of recording heads 154a. This is done inthe case of each of the other groups of recording heads 1154a forassociated mechanisms included in FIG. 1; and in the same slot of thedrum, write heads 15% are selectively energized by manual means (notshown) to enter the related coordinating control indicia, in accordancewith each of the toggle mechanisms that were used at each positioningstep. This b recording is effective, later, to select which of the fourtoggles is to be adjusted and then to be actuated, at any given time.

For automatic program-controlled operation, switching means 162a 162b isset to the position shown in FIG. 7.

The automatic operation is controlled by a cycle timer having acontinuously rotating motor, a one-revolution clutch 166 and a shaftthat operates wiping contact arms 168a, 168b 168i that cooperate withstationary contact sectors 170a, 17Gb 170i, respectively. In thedrawing, it is assumed that arms 168a, etc. rotate clockwise; andcontact sectors 170a, etc., are illustrated approximately in accordancewith a suitable timing relationship, at the start of a timing cycle.

The following control circuit is provided for controlling actuator a80by means of its solenoid-operated control valve a82. The other threetoggles have like control circuits, selected by sensing heads 152b and,optionally, using the same timer contacts where feasible. In thiscircuit, line 172 is one side of an energizing supply, and the oppositeline of the supply is represented as ground. Solenoid valve a82 isconnected in series with control contacts 174a of relay 174. Relay 176has control contacts 176a connected in a series energizing circuit forrelay 174. This circuit extends from line 172, to contact arm 168e,contact sector 170e, and contacts 176a, to relay 174 and ground. Whenrelay 174 is energized, its holding contacts 174b close. This completesan energizing circuit to line 172 including control arm 168b and contactsector 17%. The latter has a gap of about 20 at the start of therotation of arm 168b. After a minimal angle of rotation from itsstarting position shown, arm 168c energizes relay 174 (provided contacts176a are closed) and valve a82 operates actuator a80 to erect togglea68, a 70. The pressure in the actuator is sustained until the cycletimer starts its next rotation. The cycle timer stops after completingone rotation to await another operation of onerevolution clutch 166.Rotation of arms 1168b and 168c do not cause operation of actuator valvea82 if relay 176 is not energized during the time arms 1158b and 168csweep over contact sections 17% and 170c. Moreover, if relay 176 isenergized at the start of a timer rotation and if relay 176 isdeenergized during that rotation, relay 174 is deenergized promptly atthe start of the ensuing rotation of the timer.

Relay 176 is energized as follows. Relay contacts 178b operated by relay178 (or solid-state switching means) are selected and controlled bytemporary storage 15% and the recording in a related track on drum 150.Closing of relay contacts 178b energizes contact arms 168e and 10 168h.Contact arm 168e reaches contact sector t170e after about 300' from itsstart of rotation, so that relay 176 is energized at that time if thereis a control recording that causes contacts 178 to close. Relay holdingcontacts 1'76b close to complete a relay holding circuit through contactsector 170d and contact arm 168d to line .172.

Accordingly, in case a recording is sensed in one slot" of drum callingfor operation of the valve a82 of toggle actuator a80, relay 176 isenergized during one rotation under the control of temporary storageregister 158b, holding into the ensuing rotation of cycle timer 168a1668i. Valve 2182 is not operated during that first rotation. Relay 176remains energized at the start of the ensuing rotation. Closing ofcontacts 168e, 1700 at the start of that ensuing rotation energizesrelay 174. Relay holding contacts 1741) close to hold relay i174energized via contacts 1711b and 168!) during the remainder of thatensuing rotation of the cycle timer. Thus, when a recording is sensedand part of register 1S8b is set for an operation of valve a82 of toggleactuator a so, a full rotation of the cycle timer follows withoutoperation of the valve. It is during this first cycle that the input endof the related toggle is adjusted and secured in place. During virtuallythe whole next rotation, the valve a82 is operated, for etfecting atoggle-erecting power stroke of the adjusted toggle.

Relay is connected in parallel with the control of one-revolution clutch166. At the start of each rotation of the cycle timer (and the end ofthe previous rotation) relay 160 is energized, to etfect transfer of thesensed code from heads 152a and 152b to temporary storage 158a and 158b.Soon after the start of the timer cycle, contact arm i completes theenergizing circuit for solenoids 120. Those solenoids 120 which areselected by register 158a are then effective to operate solenoid valves[120 of cylinders 116. Coupling device 96 is energized selectively independence on closing of contacts 178a. This occurs at the same time asis allowed for valves 120 to effect adjustment of assembly 114, in thecircuit shown. The pressure in couplers 96 is made high enough only toadjust block 86 at the input end of the related toggles, provided thatthe related clamping solenoid valve 94 releases its clamp 92. For thisreason, couplers 96 may be pressurized during the time that assembly 114is forcibly readjusted. As an improvement it may be preferable for thisadjustment to be facilitated by delaying the operation of solenoid valve102 of the selected coupling device 96 until some time after assembly114 has been adjusted by its valves 120. An additional timer contact andan appropriate contact sector would be needed for separate, retardedpressurizing of the selected coupler 96.

Assembly 114 and pressurized coupling device a96 are thus operative toadjust block a86 at the input end of toggle a68, a7!) (or any othertoggle selected by a related relay 178). During this time it isimportant for the clamp solenoid valve a94 to be released, but to becomeset at the end of the time period provided for adjusting the input endof the toggle. The control circuit for the clamping valve-controlsolenoid is as follows.

Selective closing of contacts 17811 energizes contact arm 168h, andtoward the end of the cycle arm 168h reaches contact sector 170h forenergizing relay 182. Immediately, control contacts 182a close andenergize solenoid valve am to operate clamp a92 for locking thetheretofore adjusted block a86 securely in place. Block a86 is retainedin place after contact arm l68h leaves sector 170b, because relayholding contacts 182c close and complete a relay holding circuit viacontact sector 170g and contact arm 168g to line 172. Relay contacts 18%also close. By the time contact arm 168f has rotated about one-quarterof a revolution into the second cycle of the timer, a circuit iscompleted from line 172 via arm 168i and contact sector 170i, throughcontacts 182a, to relay 184. Then relay contacts 184a close to provide aholding circuit that keeps relay 184 energized after contact arm 168gleaves contact sector 170g to deenergize relay 182. Contacts i184b alsoclose, providing a second energizing circuit from line 172 to clampsolenoid valve a94, contacts 184b being in parallel with contacts 182athat are also closed at this time. Contacts 184b maintain theenergization of clamp-control solenoid valve a94 even after contacts182a open later, when arm 168g leaves contact sector 170g. Thus itappears that clamp solenoid valve a94 operates clamp a90 near the end ofone cycle-timer rotation and maintains that energization through the endof that rotation and during the whole ensuing time rotation. Theclamp-control solenoid valve can be held operative into the third timecycle if desired by virtue of contact sector 170f. As soon as arm 168freaches the gap in sector 170f, the energy to relay 184 via its holdingcontacts 184a is interrupted; and prior to that time, contact arm 168gparted from contact sector 170g so as to interrupt the holding circuitto relay 182. Release of relay 184 by the gap in contact sector 170ffinally deenergizes solenoid valve 94a of the clamp for the input end oftoggle a68, 270.

During the first of the time cycles described above, the assembly 114 isbeing set by pistons 116 under control of solenoid valves 120. Near theend of this first timer cycle, the end of the selected toggle can bepresumed adjusted, and the related clamp of the toggle input end is set.The clamp remains set throughout the second time cycle, and a littlelonger if desired. The related toggle-erecting actuator is activated toerect and maintain the toggle erect. This operates and holds operatedthe work output end of the multiple toggle mechanism. During thissecond" timer cycle a first" timer cycle is taking place for anotherselected toggle. This timing sequence is represented in FIG. 7A. Thedrum can be indexed at almost any time in the timer cycle.

The described operation of toggle a68, 2170 results when switches 178aand 17% close under control of a sensed control recording in a slot onthe drum. During the first 360 of timer rotation, presumably anotherpreviously adjusted and clamped toggle mechanism is executing a powerstroke; and during the 360 to 720" interval when toggle actuator n80 isexecuting a power stroke, another input end of a toggle a68a, b86 orb86a is being set, having been selected under control of the drum andcontrolled by a section of storage register 186b.

When any one of the toggles is erect, it closes its contacts 122. Seetoggle a68a, a70a in FIG. and See open switch 122 of toggle a68a, a70 inthe same figure. Each of the toggle switches 122 of the apparatus, ineach degree of freedom, is normally short-circuited or by-passed byassociated relay contacts 186a which are normally closed. Relay 186 isconnected in parallel with the valve actuator a82. Accordingly, wheneveractuator valve a82 is energized, relay 186 is also energized; and sincecontacts 186a are then open, completion of the circuit from line 172 tothe one-revolution clutch 166 of the cycle timer is dependent on closingof the related contacts 122. All the switches 122 of the apparatus arein series, each with its parallel relay contacts 186a. Consequently nonew operating cycle is started until the last-previous cycle has beencompleted. Additionally, the ensuing programcontrolled work cycle can bedelayed to allow for operation of other equipment between work strokesof the described apparatus. A coordinated function control 188 can beinterposed in the series circuit, controlled externally or by a sectionof register 158b.

It will readily appear that the foregoing control circuit whichcoordinates the mechanisms of FIG. 3 can be readily adapted to thesimpler embodiment of FIG. 2. The overlap of the setting function of onetoggle mechanism during the work stroke of another toggle mechanism inFIGS. 3-7 is not involved in FIG. 2, so the control circuit iscorrespondingly simpler. Instead, brake 64 remains set during thetoggle-setting operation in FIG. 2, and then the brake is released whenthe toggle-erecting power stroke takes place. The two cycles labeled0720 in FIG. 7A would represent one cycle of a control circuit for FIG.2.

A further modification of the embodiment in FIG. 2 is showndiagrammatically in FIGS. 8-11 at various stages of operation. Aprominent difierence in construction between the two embodiments is thatthe two blocks 108 and 108a in FIG. 2 are replaced in FIGS. 8-11 by asingle block 208. The remainder of the apparatus'is unchangedstructurally, so the same numerals are used in FIGS. 811 as in FIG. 2for like parts. FIGS. 8-11 have been simplified by omitting the brake ofgear 56 power actuators and control valves in FIG. 2 but they are to beincluded; and the manner of their sequencing will be readily understoodfrom the following description.

In FIG. 8, the parts are shown in solid lines with gear 56 at itsextreme clockwise limit of its rotation and with assembly 114 in itsextreme extended state. Gear 56 can be driven to the counterclockwiselimit by driving assembly 114 to its collapsed state and thereby movingblock 208 and cylinders 98 and 98a to their dotted-line positions, andby pressurizing unit 96 andthereby causing the toggle 68, 70 to buckleas represented in dotted lines. Next, with the input end of the togglelocked in its newly adjusted position, the toggle is caused to execute apower stroke. At the start of this stroke, coupling device 96a has itspiston 106a remote from block 208. The parts of cou' pling device 96 areillustrated in FIG. 8 in their meanposition configuration. This is thesame relationship that exists after block 208 has moved to the right,provided part 74 is free to move, and unit 96 is pressurized. At the endof the power stroke of toggle 68, 70 from the dotted-line position inFIG. 8 to the erect condition, the parts appear as shown in FIG. 9.Coupling device 96a is fully extended, not fully contracted as in FIG.8.

If the mechanism is next to return gear 56 to its clockwise extreme, areverse rotation of gear 56 compared to the change from FIG. 8 to FIG. 9can be produced as follows. Block 208 is adjusted to stay in the sameposition as it assumed to reach the configuration of FIG. 9. Couplingdevice 96a in FIG. 9 is pressurized to draw toggle-end 74a toward theright, and toggle 68a, 70a buckles as represented by dotted lines inFIG. 9. A power stroke is then executed by erecting toggle 68a, 70awhile holding its adjustable end 74a locked. The parts then assume therelationship shown in FIG. 10.

The gear 56 can again be reversed, to return from the configuration ofFIG. 10 to that of FIG. 9by adjusting block 208 to retain the positionshown in FIGS. 9 and 10, then pressurizing unit 96 to buckle toggle 68,70 as illustrated by dotted lines in FIG. 10, and then erecting thetoggle in a power stroke. Alternatively, gear 56 can be operated to thisreversed condition by first shifting block 208 to the left as shown inFIG. 8, pressurizing unit 96 to buckle the toggle 68, 70, and finallyerecting toggle 68, 70 so that the parts assume the configuration inFIG. 11.

A review of the foregoing suggests that there may be no unique controlcode for the units 116 of assembly 114 to represent any particularposition of gear 56'. This is not strictly correct. Depending on thedirection of the desired displacement of gear 56, there is a unique codefor each position in its range. The code sequence for one direction isthe same as that for the opposite direction, but inverted. FIG. 12shows, diagrammatically, part of the apparatus that may be used forcontrolling the actuating mechanism of FIGS. 8-11. In FIG. 12 it isassumed, for simplified explanation, that there are eight discretepositions in the whole operating range of gear 56, utilizing three units116 in assembly 114 of FIGS. 8 to 11. These three units 116 are relatedto each other to produce. unit displacement, double that unitdisplacement and four times that displacement, respectively. This ispurely illustrative, since many more discrete positions may be realizedin like manner merely by providing a suitably large numher of what maybe called binary-stroke related units 116.

The control apparatus of FIG. 12 includes a manually operable knob 130bearing a first pointer 132 (heavy line) that is opposite numeral 7 ofthe upper scale 134, and another pointer 136 that moves along anotherscale 138. Knob 130 is coupled to a code wheel 140 having binary codedcontact areas subdividing its 180-degree range of rotation into eightequal divisions. Knob 130 coupled to contacts 141 are in their positioncorresponding to the condition of the apparatus represented in FIG. 8.The control apparatus includes selector switch 142 shown in itsleft-hand position labeled L to R, and connected for energizing theusual valve-opening solenoids of valve 102 and 94a of FIGS. 8-11. In itsright-hand position labeled R to L (the reverse of the positionillustrated) switch 142 would enerigze solenoids to open valves 94 and102a of FIGS. 8-11.

Operation of the apparatus of FIGS. 8-11 using the manual controls ofFIG. 12 is as follows. Switch 144 is set (as shown) to prepare formanual control. With the apparatus in the condition of FIG. 8 and knob13 in the position shown, it may be desired to execute a left-torightmotion of rack 58 to the position. Knob 130 is rotated so that itspointer 132 reaches the 0" reading of its scale. Contacts 141 move alongthe contacts of code disc 140 so that the shaded contact areas of the 0binary code become effective. This correspondingly causes all units 118to collapse and assembly 114 is adjusted to its minimum length. Switch142 has been set (as shown) to its left-to-right control position. Thispressurizes coupling device 96, and opens brake valve 94 to releaseinput end 74 of the lower toggle. Input end 74 of the toggle movescorrespondingly to the right, thereby buckling the lower toggle as shownin dottedlines in FIG. 8. Using appropriate controls (not shown in FIG.12) valve 94 is then operated for locking the input end 74 of the lowertoggle, a brake on gear 56 is released (see brake 62, 64 in FIG. 2) andthe power actuator for the lower toggle is operated to erect thattoggle. As a result, rack 58 shifts from the position shown to itsopposite extreme, shown in FIG. 9.

At the end of the last operation, knob 130 has its pointer 136 oppositethe '7 reading. The code wheel contacts are in the positioncorresopnding to the minimum length of assembly 114. In this conditionof the apparatus, a right-to-left operation to position 7 can be carriedout merely by throwing switch 142 to its opposite setting, labeled R toL. Block 208 remains fixed (FIG. 9) but opening of valve 94a releasesthe input end 74a of theupper toggle while at the same time operation ofvalve 102a pressurizes coupling device 96a. This causes unit 96a toassume its mean length, and the upper toggle buckles as represented indotted lines. In the ensuing powered operation of the apparatusresulting from erection of the upper toggle, the lower rack 58 is drivenfrom its extreme position at the right in FIG. 9 to the left extretne asshown in FIG. 10.

Finally, operation of pointer 132 to the original position representedin FIG. 12 and adjustment of switch 142 to the original position as inFIG. 12, results in elongation of assembly 114 to its maximum length,motion of block 208 to the extreme left-hand position, buckling of thelower toggle as shown in dotted lines in FIG. when coupling device 96 ispressurized, and then the ensuing power stroke of the lower toggledrives rack 58 from left to right, ending in the position shown in FIG.11.

Comparing FIGS. 8-11 with FIG. 2, it is seen that the dual toggleactuating mechanisms in both forms of construction are capable of thesame manner and range of operation. This occurs despite the differentuse of two reversely moving control blocks 108 in FIG. 2 and a singlecontrol block 208 in FIGS. 8-11. This represents but one variation thatcan be introduced. In each of the examples discussed above, the dualtoggles utilize separate hydraulie or pneumatic cylinders for toggleerection, but an obvious variant contemplated (but omitted here in theinterest of consciseness) involves the use of a single actuating pistonand cylinder for both toggles of a pair.

As a still further detail, the two toggles in FIG. 2 may be mechanicallydesigned for operation by a single erecting actuator, if desired.

The foregoing illustrative embodiments of the invention in its variousaspects are subject to a further latitude of variation and variedapplication by those skilled in the art. Consequently, the inventionshould be construed broadly in accordance with its full spirit andscope.

What is claimed is:

1. Apparatus for operating a work element, including plural toggles eachhaving a pair of links pivoted together at a knee, said toggles havingrespective adjustable input ends and having work output ends, meansconnecting said work output ends to the work element, power actuatingmeans connected to the knees of the toggles for erecting the toggles,and means operative with respect to any selected one of said toggleswhile buckled for securely adjusting the input end of the selectedtoggle to a position corresponding to that which should be reached bythe work element when said selected toggle is subsequently erected bysaid power actuating means, said plurality toggles including first andsecond toggles whose work output ends have respective connections tosaid work element arranged to cause operation thereof in one directionduring erection of said first toggle with the input end thereof in anadjusted position and to cause operation thereof in the oppositedirection during erection of said second toggle with the input endthereof in an adjusted position.

2. Apparatus for operating a work element as in claim 1, furtherincluding means for locking the input end of each said toggle in itsadjusted position prior to erection of its toggle.

3. Apparatus for operating a work element as in claim 1, furtherincluding means for maintaining control of the work output element whilethe input end of said selected toggle is being adjusted.

4. Apparatus for operating a work element as in claim 1, furtherincluding braking means for holding said work element fixed while theinput end of any one of said plural toggles is being adjusted.

5. Apparatus for operating a work element as in claim 1, furtherincluding means for maintaining control of the work element while theinput end of each selected one of said toggles is being adjusted, andmeans for locking the adjusted input end of the selected toggle inpreparation for the ensuing toggle erecting operation.

6. Apparatus for operating a work element as in claim 1, wherein saidfirst and second toggles are disposed side-by-side, said work elementincluding a shaft, and wherein said means connecting the output ends ofsaid first and second toggles to said work element is arranged to elfectrotation of the shaft in one direction or the opposite direction independence on which of the toggles is being erected.

7. Apparatus for operating a work element as in claim 1, wherein saidwork element comprises a rotatable shaft, said first and second togglesbeing disposed side-by-side and having their work output ends arrangedto move in the same direction in executing their power strokes, andmeans connecting the output ends of said first and second toggles tosaid work element including a rotary member on said shaft and positivedriving means between said work output ends and opposite sides of saidrotary member.

8. Apparatus for operating a work element as in claim 1, including acommon adjustment means for said input ends of said toggles.

9. Apparatus for operating a work element as in claim 1, wherein saidfirst and second toggles are disposed sideby-side and including a commonadjustment means for the input ends of both said toggles.

10. Apparatus for operating a work element as in claim 1, wherein saidfirst and second toggles are disposed side-by-side and including acommon adjustment means for the input ends of both said toggles coupledin opposite driving relationship to said input ends of the toggles.

11. Apparatus for operating a work element as in claim 1, wherein saidfirst and second toggles are disposed sideby-side and including a commonadjustment means for the input ends of both said toggles coupled in thesame driving relationship to said input ends of the toggles.

12. Apparatus for operating a work element as in claim 1, wherein saidplural toggles include third and fourth toggles arranged so that saidthird toggle while being erected can drive the work element in said onedirection and the fourth toggle while being erected can drive the workelement in said opposite direction, and means for coordinating theoperation of said power actuating means and said means for securelyadjusting the input ends of the toggles so that, during the time one ofsaid toggles has its input end in a previously adjusted position foreffecting operation of said work element to one position, the input endof another toggle is adjusted by said adjusting means to a positioncorresponding to the ensuing position to which the work element is to beoperated from said one position, irrespective of the required directionof operation from said one position to said ensuing position.

13. Apparatus for operating a work element as in claim 12, saidapparatus including a locking device for locking the input end of eachof said toggles, and said coordinating means including means formaintaining efiective the locking device of said one of said fourtoggles to hold the input end thereof in an adjusted position whilemaintaining ineffective the locking device of another of said toggleswhose input end is being adjusted.

14. Apparatus in accordance with claim 12, wherein said adjusting meansincludes a common adjusting unit for all said toggles, and respectivecoupling devices for enforcing cooperation between said common adjustingunit and the input end of a selected one of said toggles.

15. Apparatus in accordance with claim 14, wherein each said couplingdevice has means constraining it to assume a mean length when the inputend of the related toggle is in enforced cooperation with said adjustingunit and wherein each said coupling device has means for accommodating ashift in one direction of one end thereof from its mean-length positionand for accommodating a shift in the opposite direction of the other endthereof from its mean-length position, the maximum extent of each saidshift being at least the range of adjustment of said adjusting unit.

16. Apparatus for operating a work element as in claim 12, wherein saidadjusting means includes a common adjusting unit for said toggles, andrespective selectively operable coupling devices for enforcingcooperation between said common adjusting unit and the input end of aselected one of said toggles.

, 17. Apparatus for operating a work element as in claim 12, furtherincluding respective locking means for the input ends of said toggles,and means for maintaining the locking means for one of said toggleseffective while the input end of another of said toggles is not lockedand is being adjusted.

18. Apparatus for operating a work element as in claim 17, wherein saidadjustment means includes a common adjusting unit for all said toggles,and respective selectively operable coupling devices for enforcingcooperation between said common adjusting unit and the input end of aselected one of said toggles.

19. Apparatus for operating a work element as in claim 16, wherein eachsaid coupling device has means constraining it to assume a mean length,and herein each said coupling device has means for accommodating a shiftin one direction of one end thereof from its meanlength position and foraccommodating a shift in the opposite direction of the other end thereoffrom its meanlength position, the maximum extent of each said shiftbeing at least the range of adjustment of said adjusting unit.

20. Apparatus in accordance with claim 1, wherein said means foradjusting the input end of said toggle includes plural combination-coderesponsive elements.

21. Apparatus for operating a work element in accordance with claim 1,wherein said adjusting means includes a common adjustment means for saidinput ends of said toggles, said apparatus including means forselectively locking the input end of one of said toggles in positionwhile the latter is being erected by said power actuating means, andcoupling means for forcing each of the unlocked input ends of saidtoggles toward a position conforming to said common adjustment means.

22. Apparatus for operating a work element to successive selectedpositions, said apparatus having plural toggles each having first andsecond links pivoted together at a knee, said toggles having respectiveseparately adjustable input ends and having work output ends connectedto the work element, power actuating means connected to the knees of thetoggles for erecting the toggles, and means for adjusting the input endof one of said toggles while a second of said toggles is being erectedunder control of its previously adjusted input end.

23. Apparatus for operating a work element to successive selectedpositions in accordance with claim 22, including locking means for theinput ends of each of said toggles, and means for coordinating theadjusting means and the locking means for the input ends of saidtoggles, said coordinating means controlling the locking means of saidone toggle to unlock the input end thereof and causing said adjustingmeans to adjust said unlocked input end thereof during the time when theinput end of said toggle is locked.

24. Apparatus for operating a work element in accordance with claim 22,including a common adjustment unit for said plural toggles andindividual coupling devices between said common adjustment unit and saidinput ends of said toggles, each of said coupling devices having anoutput end connected to the input end of a respective one of saidtoggles and an input end connected to said common adjustment unit, andeach of said coupling devices including means for accommodating enforcedenlargement and contraction thereof from a mean configuration andincluding means for forcing it toward said mean configuraton forestablishing a prescribed relationship between the common adjustmentunit and the input end of each of said toggles when the coupling devicereaches said mean configuration.

25. Apparatus for actuating a work element directly from each of aseries of successive selectively controlled positions to the nextposition of the series, including plural actuating devices each havingan input end that is adjustable independent of the adjustable input endof another of said plural actuating devices, and each of said actuatingdevices having an output end connected to the Work element and each ofsaid actuating devices having a fixed length when fully actuated andhaving a length prior to actuation that is variable in dependence on theposition of the input end thereof and on the position of the workelement, power means for separately operating each of said actuatingdevices, adjustment means for operating each of said input ends to anyselected position within a range and means for securing each of saidinput ends in any selected position established by said adjustmentmeans, and means coordinating said adjusting and securing means and saidpower means so that, during the time that the input end of one of saidactuating devices is secured in a selected position, the input end ofanother of said actuating devices is unsecured so as to be adjustable 17by said adjustment means and during the same time said one of saidactuating devices is operated by said power means to assume its fixedlength, thereby actuating said work element in a power stroke to aposition corresponding to the adjusted position of the input end of theactuating device that is operated.

26. Apparatus in accordance with claim 25, wherein said plural actuatingdevices include at least first and second actuating devices arranged tooperate said work element in mutually opposite directions.

27. Apparatus in accordance with claim 25, wherein said plural actuatingdevices include two actuating devices arranged to operate said workelement in one direction and two actuating devices arranged to operatesaid work element in the opposite direction, said coordinating meansbeing arranged to cause the adjustment means to adjust the input end ofone of said actuating devices to a position corresponding to a newposition that the work element is to assume while the securing means iseffective to maintain arrested a previously adjusted input end ofanother one of said actuating devices that is thus operable to drivesaid work element to a position corresponding to the position of saidpreviously adjusted input end, whereby the apparatus is operable toeffect sequential selectively controlled operations of said work elementfrom any position to any other position in its range in either directionthat may be required while preparing the input end of another of saidactuating devices for controlling the ensuing operation.

28. Apparatus for operating a work element as in claim 12, wherein saidadjusting means includes a common adjusting unit for said toggles, andrespective coupling devices for enforcing cooperation between saidcommon adjusting unit and the input end of a selected one of saidtoggles, each of said coupling devices having an output end connected tothe input end of a respective one of said toggles and an input endconnected to said common adjusting unit and each of said couplingdevices including means for accommodating enforced enlargement andcontraction thereof from a mean configuration and including means forforcing it toward said mean configuration for establishing a prescribedrelationship between the common adjusting unit and the input end of eachof said toggles when the coupling device reaches said meanconfiguration.

29. Apparatus for operating a work device to successive selectedpositions, said apparatus including a toggle having first and secondtoggle links pivoted together at a knee, said first link having anadjustable end remote from said knee forming the control end of thetoggle, said second link having an end remote from said knee forming theoutput end of the toggle and operatively connected to said work device,power actuating means connected to said knee for erecting the toggle,control information supply means for providing a sequence of work-deviceposition representations, means responsive to said control informationsupply means for adjusting said control end of the toggle to asuccession of positions, and coordinating means causing said adjustingmeans to effect successive adjustments in the intervals betweentoggle-erecting strokes of said power actuating means.

30. Apparatus for operating a work device to successive selectedpositions, said apparatus including a toggle having first and secondtoggle links pivoted together at a knee, said first link having anadjustable end remote from said knee forming the control end of thetoggle, said second link having an end remote from said knee forming theoutput end of the toggle and operatively connected to said work device,power actuating means connected to said knee for erecting the toggle,means for adjusting said control end of the toggle to a succession ofprescribed positions, said adjusting means including pluraladjustment-control portions representing a prescribed program ofadjustments and means responsive to said control portions for operatingsaid control end of said toggle to predetermined adjusted positions, andcoordinating means causing said adjusting means to efiect successiveadjustments in the intervals between toggleerecting strokes of saidpower actuating means.

31. Apparatus for operating a work device in accordance with claim 29,wherein the actuating means is related to the toggle for efiectingsubstantially full erection of the toggle despite variations in theadjusted positions of said control end thereof.

32. Apparatus for operating a work device in accordance with claim 29,wherein the operative stroke of said actuating means is of variablelength to accommodate various degrees of buckling of the toggle at thestarts of a succession of toggle-erecting strokes.

33. Apparatus in accordance with claim 29, further including meanscoordinated by said coordinating means for locking the output end of thetoggle in the intervals between said toggle-erecting strokes.

34. Apparatus in accordance with claim 29, including means coordinatedby said coordinating means for maintaining control of said work deviceduring the intervals between said toggle-erecting strokes.

35. Apparatus in accordance with claim 29 wherein said adjusting meansincludes means for linearly shifting said control end of the toggle andmeans separate from said shifting means for arresting said control endof the toggle during said toggle-erecting strokes.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS 3,291, 18? 5/ 1966 Devol 73-88.5 R 3,279,62410/1966 Devol 2l4l 3,283,918 ll/1966 Devol 2141 3,306,471 '2/1967 Devol214-1 11423185 7/1964 Knowles 74-520 2,588,489 3/1952 Day 74-5202,369,362 2fl1945 Marziani 74520 1,042,381 10/1912 Baker 74-520 SAMUELSCOTT, Primary Examiner W. S. RATLIFF, 1a., Assistant Examiner US. Cl.X.R. 214-1 E

